1. Field of the Invention
The present invention relates to a sheet mounting apparatus attachable to sheet processing apparatus including an image-forming apparatus such as a copier, printer or facsimile machine, for holding sheets to be fed to a predetermined position in the sheet processing apparatus. More particularly, the invention relates to a sheet mounting apparatus for mounting a variety of sizes of sheets on a sheet mounting plate.
2. Description of the Related Art
Generally, with a sheet processing apparatus such as an image-forming apparatus for continuously performing a predetermined process for a plurality of objects in sheet form, the sheets must be fed successively to a predetermined position in the apparatus. For this purpose, the sheet processing apparatus has a sheet mounting apparatus such as a sheet feed cassette or sheet feed tray for storing a plurality of sheets. The sheet mounting apparatus has restricting members for restricting the movement of sheets in a direction perpendicular to a sheet feeding direction, and stores a plurality of sheets of the same size.
On the other hand, some sheet processing apparatuses are constructed to process plural types of sheets having different sizes. A sheet mounting apparatus applicable to such a sheet processing apparatus must determine a sheet position in the direction perpendicular to the sheet feeding direction for each of the plurality of sizes. Thus, the restricting members may be set to positions corresponding to each sheet size. Particularly where sheets are fed to the sheet processing apparatus with reference to a middle position in the direction perpendicular to the sheet feeding direction, and when the sheets to be fed are changed from one size to another, the right and left restricting members in the sheet mounting apparatus must be moved by the same amount in opposite directions.
A sheet processing apparatus which selectively performs processes for sheets of different sizes may accept a plurality of sheet mounting apparatuses for storing the different size sheets. Where sheets of a different size are fed from each sheet mounting apparatus, all the sheet mounting apparatuses must have a common reference position in the direction perpendicular to the sheet feeding direction. Otherwise, the processing position in the sheet processing apparatus would be varied for each size of the sheets. It would then be impossible to process the sheets in a proper position.
Where a plurality of sheet mounting apparatuses are attached to a conventional sheet processing apparatus, the position in the sheet processing apparatus to which each sheet mounting apparatus is attached, or the positions of restricting members in each sheet mounting apparatus, is/are adjustable in order to secure for all the sheet mounting apparatuses a precisely uniform reference position in the direction perpendicular to the sheet feeding direction.
However, a conventional sheet mounting apparatus requires an operation to adjust the position in the sheet processing apparatus to which the sheet mounting apparatus is attached, or adjust the positions of restricting members in the sheet mounting apparatus. This operation is carried out by loosening fastening devices of the restricting members with a tool, then moving the sheet mounting apparatus or the restricting members, relying on eye measurement, and tightening the fastening devices with the tool. Thus, a necessary amount of movement of the sheet mounting apparatus or the restricting members cannot be grasped accurately. The sheet mounting apparatus or the restricting members could move in time of tightening the fastening devices. It is difficult to secure a precisely uniform position for feeding sheets from a plurality of sheet mounting positions. The adjusting operation needs to be repeated, thereby requiring an extended operating time.
A plurality of sheet mounting apparatuses attachable to a sheet processing apparatus include the type that can detect and/or indicate a size of sheets stored, based on the positions of restricting members. However, when the positions of the restricting members are adjusted in the sheet mounting apparatus, an error could occur in the size detection or indication. Then, the sheet processing apparatus would misrecognize the size of sheets stored in the sheet mounting apparatus. There also occurs a discrepancy between the size indicated by the sheet mounting apparatus and the size of sheets stored thereon.
An object of the present invention is to provide a sheet mounting apparatus which allows an amount by which a restricting section should be moved to be grasped accurately and easily, prohibits movement of the restricting section in time of fastening the restricting section, allows positions of the restricting section to be adjusted accurately and just by a necessary amount, allows an operation for adjusting a sheet feed position to be carried out easily and in a short time, and produces no error in size detection or indication due to movement of the restricting section.
To achieve the above-mentioned object, the invention provides a sheet mounting apparatus comprising:
a main body for mounting a variety of sizes sheets on a sheet mounting plane;
a restricting section movable to the main body in a first direction which is parallel to the sheet mounting plane of the main body and perpendicular to a second direction which is a sheet feeding direction, according to a size of sheets on the sheet mounting plane, for restricting movement of the sheets;
a reference position regulating section for regulating a reference position of the restricting section in the first direction; and
an adjusting section for selectively moving the reference position regulating section to one of a plurality of positions in the first direction.
In the above construction according to the invention, the reference position regulating section for regulating the reference position of the restricting section which restrict movement of the sheets in the first direction is moved by the adjusting section selectively to one of a plurality of positions in the first direction. Thus, when the reference position regulating section moves to one of the plurality of positions in the first direction, the reference position of the restricting section shifts in the first direction. In this way, the reference position is adjusted easily and accurately.
According to the invention, the reference position regulating section for regulating the reference position of the restricting section which restrict movement of the sheets in the first direction is moved by the adjusting section selectively to one of the plurality of positions in the first direction, the reference position of the restricting section is shifted in the first direction, to adjust the reference position easily and accurately. As a result, an operation to adjust a sheet feed position can be carried out easily and in a short time.
In the invention it is preferable that the reference position regulating section is a rotatable element rotatable with movement of the restricting section, and movable relative to the main body within a predetermined range in the first direction; and
the adjusting section includes an eccentric cam which is supported coaxially with the rotatable element to be placed selectively in one of a plurality of rotational positions and has a peripheral surface contacting side surfaces of a cam guide formed in the main body, which side surfaces extend parallel to the second direction.
In this construction according to the invention, the position of the rotatable element in the first direction varies with the distance from the center of rotation of the eccentric cam to positions of contact between the peripheral surface of the eccentric cam and the side surfaces of the cam guide extending parallel to the second direction. Thus, when the eccentric cam is rotated to a predetermined rotational position, the reference position of the restricting section shifts in the first direcion. The reference position is adjusted easily and accurately only by the rotation of the eccentric cam.
According to the invention, the eccentric cam is rotated to a predetermined rotational position by varying the position of the rotatable element in the first direction based on the distance from the center of rotation of the eccentric cam to the positions of contact between the peripheral surface of the eccentric cam and the side surfaces of the cam guide extending parallel to the second direction. This results in a shift of the reference position of the restricting section in the direction perpendicular to the second direction. The reference position is thus adjusted easily and accurately only by the rotation of the eccentric cam.
In the invention it is preferable that the adjusting section includes a control member which is disposed below an upper surface of a sheet mount of the main body so as to be operated from the upper surface side of the sheet mount, and fixed to an upper surface of the eccentric cam to be coaxial with the axis of rotation of the cam.
In this construction according to the invention, the control member operable to rotate the eccentric cam is disposed so as to be operated from the upper surface side of the sheet mount, without contacting the bottom of a lowermost sheet of the sheets stacked on the sheet mounting plane. Thus, an operation to adjust the reference position of the restricting section in the first direction is carried out easily from above the sheet mount, with the control member not interfering with sheet feeding.
According to the invention, with the control member operable to rotate the eccentric cam and disposed so as to be operated from the upper surface side of the sheet mount, without contacting the bottom of the lowermost sheet of the sheets stacked on the sheet mounting plane, an operation to adjust the reference position of the restricting section in the first direction can be carried out easily from above the sheet mount, and the control member does not interfere with sheet feeding.
In the invention it is preferable that the reference position regulating section is a rotatable element rotatable with movement of the restricting section, and movable relative to the main body within a predetermined range in the first direction; and
the adjusting section includes a screw meshed with a support portion of the rotatable element in the first direction to be placed selectively in one of a plurality of rotational positions.
In this construction according to the invention, the position in the first direction of the support portion of the rotatable element which regulates the reference position of the restricting section varies with the rotational position of the screw. Thus, when the screw is rotated to a predetermined rotational position, the reference position of the restricting section shifts in the first direction. The reference position is adjusted easily and accurately only by the rotation of the screw.
According to the invention, the screw is rotated to vary the position in the first direction of the support portion of the rotatable element which regulates the reference position of the restricting section. By rotating the screw to a predetermined rotational position, the reference position of the restricting section can be shifted in the first direction. Thus the reference position can be adjusted easily and accurately only by the rotation of the screw.
In the invention it is preferable that the adjusting section includes a control member which is disposed so as to be operated from a side surface side of a sheet mount of the body, and fixed to one end of the screw to be coaxial with the screw.
In this construction according to the invention, the control member operable to rotate the screw is disposed so as to be operated from the side surface side of the sheet mount. Thus, an operation to adjust the reference position of the restricting section in the first direction is carried out outside the sheet mount, without requiring the sheets to be removed from the sheet mount.
According to the invention, with the control member operable from the side surface side of the sheet mount to rotate the screw, an operation to adjust the reference position of the restricting section in the first direction can be carried out outside the sheet mount easily. The sheets need not be removed from the sheet mount in time of the adjusting operation.
In the invention it is preferable that the apparatus further comprises a size indicator movable in the same direction and by the same amount as those of the reference position regulating section, for indicating positions of ends of the sheets on the sheet mount of the main body in the first direction.
In this construction according to the invention, the size indicator is movable in the same direction and by the same amount as those of the reference position regulating section regulating the reference position of the restricting section. Thus, after the reference position of the restricting section is shifted, the reference position and size indicator remain in the same positional relationship, whereby a sheet position on the sheet mount is indicated accurately.
According to the invention, by moving the size indicator in the same direction and by the same amount as those of the reference position regulating section regulating the reference position of the restricting section, the positional relationship between the reference position and size indicator remains unchanged even after the reference position of the restricting section is shifted. Consequently, a sheet position on the sheet mount can be indicated accurately at all times.
In the invention it is preferable that the apparatus further comprises a size detector movable in the same direction and by the same amount as those of the reference position regulating section, for detecting positions of the restricting section on a sheet mount of the main body in the first direction.
In this construction according to the invention, the size detector is movable in the same direction and by the same amount as the reference position regulating section regulating the reference position of the restricting section. Thus, after the reference position of the restricting section is shifted, the reference position and size detector remain in the same positional relationship, whereby the size of sheets placed on the sheet mount is detected accurately.
According to the invention, by moving the size detector in the same direction and by the same amount as those of the reference position regulating section regulating the reference position of the restricting section, the positional relationship between the reference position and size detector remains unchanged even after the reference position of the restricting section is shifted. Consequently, the size of sheets placed on the sheet mount can be detected accurately at all times.